Scrooge crept towards it, trembling as he went; and following the finger, read upon the stone of the neglected grave his own name, Ebenezer Scrooge . . . "Spirit!" he cried, tight clutching at its robe, "hear me! I am not the man I was. I will not be the man I must have been . . . "

-- "A Christmas Carol"

One and a half centuries after Charles Dickens wrote those lines, a social psychologist in Colorado conducted an unusual experiment.

Thomas Pyszczynski and his colleagues tracked down men and women walking down a street in Boulder and asked them to take a short survey. Some people were interviewed in front of a funeral home and others were interviewed three blocks away. Everyone received identical surveys.

The survey asked people their opinions about a number of charities. In return for completing the survey, the psychologists offered to make a small donation to a charity of each person's choice.

Pyszczynski found that people who answered the survey while standing in front of the funeral home -- which had a large sign reading "Howe's Mortuary" -- were more positive about charitable donations than those interviewed 150 feet away. Not only that, the people interviewed near the funeral home were more likely than those interviewed three blocks away to say that kindness and generosity were qualities that were personally important to them.

"Scrooge's encounter with the Ghost of Christmas Future and seeing his name on the grave makes him shift toward becoming a more kind and giving person," Pyszczynski said. The Colorado experiment and a number of others have found that "when people are reminded of death, they are motivated to view charities in a positive light."

The "Scrooge Effect" prompted Pyszczynski and colleagues Sheldon Solomon at Skidmore College in New York and Jeff Greenberg at the University of Arizona to develop an idea known as Terror Management Theory.

The theory suggests that when people face explicit dangers, they usually respond rationally -- they get out of the path of a hurtling car, for example. But when terrors are on the fringes of awareness, as was the case with the Colorado pedestrians and the funeral home, people respond with defenses that are primarily psychological. One of these psychological defenses is to seek connections to things larger than ourselves -- to values and ties that will outlive our physical existence.

"Reminders of mortality bolster our sense that we are valuable parts of a meaningful world, and one way we do that is by being good people and helpful, by doing charitable things," Greenberg said. "This is why rich people who get rich by pretty ruthless methods often become philanthropists later in life. We want to feel like we are moral and spiritual beings who can transcend just being mortal creatures -- and feeling moral sustains that feeling."

Reminders of death do not always prompt people to become kind and generous. Pyszczynski and others have found that such reminders can also prompt people to become jingoistic.

"People respond to fears in a variety of ways," Pyszczynski said. "They shore up their system of meaning by putting down people who challenge their view of the world, and also by trying to live up to the standards valued by their cultures."

At its most basic level, Terror Management Theory argues that humans are uniquely burdened with the knowledge that they are going to die. Children can be protected against such fears by the assurances of their parents, but as they grow up, they realize that their parents can't protect them from everything. Since death is inevitable, people invent psychological defenses against it.

"We keep our terror under control by feeling like we are more than just animals doomed to obliteration, but that we are special beings with a soul and that we will transcend our own deaths either literally or symbolically," Greenberg said.

If Scrooge's conversion is only a response to fear, does Terror Management Theory imply that God and religion are only figments of human imagination, psychological levees constructed against the rising tides of our fears?

"The theory can't address whether there is or isn't an afterlife, or there is and isn't a God, but it suggests we want to believe in those things in order to quell our anxieties," Greenberg said. "As our cultures developed, they developed ways to handle our psychological anxieties with ideas of a soul and afterlife, and symbolic ways to achieve immortality."